Stairway suspended from stringers



July 18, 1967 LBLUM ETAL.

STAIRWAY SUSPENDED FROM STRINGERS Filed Dec. 10, 1964 INVENTORS. Jaws 5/11 A/J// /1/1//// W United States Patent Office 3,331,467 Patented July 18, 1967 3 331 467 STAIRWAY SUSPEl' IDE D FROM STRINGERS Louis Blum and William J. Horgan, In, Pittsburgh, Pa., assignors to Blumcraft of Pittsburgh, Pittsburgh, Pa., a firm Filed Dec. 10, 1964, Ser. No. 417,368

4 Claims. (Cl. 182-106) ABSTRACT OF THE DISCLOSURE Laterally spaced load carrying tringers arch upwardly from a lower floor level to an upper fioor level and are rigidly anchored at both ends. A series of treads are suspended from the stringers by means of balusters rigidly afiixed to the stringers. On each side of the stairway the balusters extend upwardly from the stringer for connection to a handrail which also arches upwardly from the lower to the upper floor level, and which is anchored at both ends.

This invention relates to an improved stairway and more particularly to a novel combination of stairway components which achieves an unusually sturdy structure.

conventionally, simple stairways have been characterized by the familiar jagged cut stringer to which the steps, railing unit, riser and items of ornamentation were fastened. The opinion has been universally held in the art that a stringer stairway having this type of construction was needed to handle typical design loadings in various desired applications. This approach has prevented further development in this fundamental and widely applied art.

It is therefore an object of thi invention to provide a stairway which improves upon the strength of conventional prior art stringer stairways while providing a radically different structure thereby freeing this art from past conventions.

It is a further object of this invention to simplify the construction of stairways thereby promoting speed and ease in erection.

A still further object of this invention is to provide a stairway whose structure permits the economical use of materials while providing for wide latitude in individual design initiative among architects, fabricators and erectors in many different stairway applications.

-Other objects and advantages to the present invention will be apparent from the following detailed description of the stairway according to this invention.

Referring to the drawings:

FIGURE 1 is a perspective view of the entire stairway as it might be placed in a particular application.

FIGURE 2 is a partial side view taken from the right of FIGURE 1 illustrating a terminal portion of the rigid supporting means and handrail showing the points of attachment of typical steps and balusters.

FIGURE 3 is a View of FIGURE 2 taken from the left with parts of the handrail and rigid supporting means broken and shown in section.

FIGURE 4 is a partial cross-sectional view taken along the lines and arrows IV-IV of FIGURE 2 showing typical means for mounting the balusters to the rigid supporting means.

Referring now specifically to the drawings, the novel stairway constructed according to this invention can best be understood by referring to FIGURE 1. The stairway supporting means 1 and 2 are appropriately placed so as to position the stairway in its desired location as well as to firmly anchor the stairway to its environmental structure. For example, supporting means, as illustrated is segmented into three individual parts 10, 11 and 12 which are joined together in any convenient conventional manner to form any desired configuration consistent with the teaching contained herein. Segments 10, 11 and 12 of supporting means 1, are fastened to the wall at B and to the floor at A, in any convenient conventional manner. Supporting means 2 is composed of two segments 20 and 21 and is attached to a matching member 22 located on the baluster posts shown as a group at 24 which are conventionally fastened to the elevated level 25 to which the stairway reaches.

Supporting means 1 and 2 placed as they are in FIG- URE I perform a function dissimilar to standard stairway stringers with important new advantages. The strength of the new stairway is materially increased over conventional stringer stairways and therefore stairways of this type can be designed for a wide variety of applications and loadings hitherto impractical or even impossible to achieve in most applications.

The handrails 3 and 4 are fastened or anchored at C and D or at E where the stairway handrail is fastened to or joins the handrail 5 above the elevated level 25. The detail of the side view of FIGURE 2 shows the position of the handrail 4 fastened at C in relation to supporting means 2 and the anchoring of portion 20 of supporting means 2 at A (also shown in FIGURE 1).

The lateral rigidity of the stairway according to this invention is uniquely achieved by the cooperation of the handrails 3 and 4, the supporting means 1 and 2 and collectively the baluster posts 8 and treads 9. The baluster posts 8 (the designation characterizing all the baluster posts on both sides of the stairway attached to treads illustrated in FIGURE 1) are fastened in any known manner to the handrails (see FIGURE 2 at F) and to the treads 9 and in addition are fastened to the supporting means. This latter attachment being accomplished by any fastening means well known in the art as by screw 15 and 16 in FIGURES 2 and 4 where post 8 is shown fastened to stringer 2.

In the preferred embodiment of this invention shown in all of the drawings, the handrails 3 and 4 are mounted in an offset fashion from the baluster posts 8 (see FIG- URE 3). The completed structure then takes on the appearance of a four cornered box in which part of the top has been removed but all of the corners remain intact. It is this space frame arrangement which gives the stairway of this invention its unusual stability and high loading strength. The lateral stability of the arrangement is assured by the box-like structure in end view (as shown in FIG. 3) which is highly successful in resisting lateral deforming forces. The high loading potential which is characteristic of this invention is achieved by the unique cooperation of the handrails 3 and 4 and the supporting means which receive the load placed on treads 9 through the baluster posts 8. The distribution of this load to both the railings 3 and 4 and the supporting means 1 and 2 imparts an unexpected benefit to the entire stairway structure. Considerable latitude in the choice of materials for the component parts is now possible with the designers of individual stairways for particular applications being free to distribute the load bearing capability between the various components by simply choosing materials of the desired strengths. The particular embodiment described was chosen primarily for purposes of clearly illustrating the manner in which the supporting means and the handrails can be anchored to the floor and wall supporting surfaces to make maximum use of their load supporting capabilities in the particular configurations shown.

It will be appreciated by one of ordinary skill in the art to which this invention pertains that it is capable of being practiced in a wide variety of applications without departing from the spirit of the foregoing disclosure or the scope of the appended claims.

We claim:

1. In an inclined stairway, the combination comprising (A) a pair of laterally spaced load bearing stringers arching from the lower to the upper end portions thereof and adapted for being rigidly anchored at both ends,

(B) two series of laterally spaced vertically extending balusters respectively on the outer sides of, rigidly aflixed to and supported by said stringers,

(1) the upper end portions of said balusters extending upwardly from said stringers, and

(2) the lower end portions of said balusters depending from said stringers,

(C) a series of treads each having opposite end portions rigidly afiixed respectively to the lower end portions of opposed balusters, and

(D) a pair of handrails disposed respectively over said stringers and each aifixed to the upper end portions of the associated balusters in spaced relation to the underlying stringers.

2. The combination according to claim 1 wherein the stringers extend over the treads in straight lines parallel to the stairway, and the lower end portions of the stringers extend over the lowermost tread and then vertically downwardly past the same to their points of rigid anchorage.

3. The combination according to claim 2 wherein means extending laterally inwardly from each series of balusters connect the handrails to the balusters and position them inwardly oi the balusters.

4. The combination according to claim 3 wherein the handrails are parallel to the stringers and the lower end portions thereof extend vertically downwardly generally parallel to the lower end portions of the stringers, being adapted for having their terminal portions rigidly anchored.

References Cited UNITED STATES PATENTS 247,106 9/1881 Pratt 52-184 2,466,708 4/ 1949 Kamps 182l 3,284,970 11/1966 Stowasser 52143 FOREIGN PATENTS 10,977 1842 France. 808,435 1l/1936 France.

JOHN E. MURTAGH, Primary Examiner. c. G. MUELLLER, Assistant Examiner. 

1. IN AN INCLINED STAIRWAY, THE COMBINATION COMPRISING (A) A PAIR OF LATERALLY SPACED LOAD BEARING STRINGERS ARCHING FROM THE LOWER TO THE UPPER END PORTIONS THEREOF AND ADAPTED FOR BEING RIGIDLY ANCHORED AT BOTH ENDS, (B) TWO SERIES OF LATERALLY SPACED VERTICALLY EXTENDING BALUSTERS RESPECTIVELY ON THE OUTER SIDES OF, RIGIDLY AFFIXED TO AND SUPPORTED BY SAID STRINGERS, (1) THE UPPER END PORTIONS OF SAID BALUSTERS EXTENDING UPWARDLY FROM SAID STRINGERS, AND (2) THE LOWER END PORTIONS OF SAID BALUSTERS DEPENDING FROM SAID STRINGERS, (C) A SERIES OF TREADS EACH HAVING OPPOSITE END PORTIONS RIGIDLY AFFIXED RESPECTIVELY TO THE LOWER END PORTIONS OF OPPOSED BALUSTERS, AND (D) A PAIR OF HANDRAILS DISPOSED RESPECTIVELY OVER SAID STRINGERS AND EACH AFFIXED TO THE UPPER END PORTIONS OF THE ASSOCIATED BALUSTERS IN SPACED RELATION TO THE UNDERLYING STRINGERS. 